Thanks guys for your feedback.
I've started doing minor adjustments (i.e. removal of extra unnecessary calls and text modifications). So far it works, maybe I can start thinking to design a simple application to give a GUI to this xml file.
A proposal: it will be nice if the checklist could be "per operator", so that any virtual airline can have its own sets of calls as per SOP. Maybe having a separate file in each livery with fallback to the default one in case of missing checklist?